Heat pump apparatus

Patent metadata

Field	Value
Publication number	US-10473367-B2
Application number	US-201414891903-A
Country	US
Kind code	B2
Filing date	May 21, 2014
Priority date	May 24, 2013
Publication date	Nov 12, 2019
Grant date	Nov 12, 2019

Abstract

A heat pump apparatus, including: a two-cylinder compressor including: an electric motor; two compression units to be driven by the electric motor, the two-cylinder compressor being structured to switch between two operation modes including single operation in which one of the compression units is brought into a non-compression state, and parallel operation in which both the compression units are brought into a compression state; an inverter drive control device supplying drive power to the electric motor of the two-cylinder compressor; an operation mode detecting-determining unit determining a current operation mode based on an electric signal acquired from the inverter drive control device; and a capacity control device determining a rotating frequency of the electric motor so that a temperature of a target object is brought close to a set value, to thereby control the inverter drive control device based on a result of determination of the operation mode detecting-determining unit.

First claim

The invention claimed is:

1. A heat pump apparatus, comprising:
a two-cylinder compressor including
an electric motor, and
two compression units to be driven by the electric motor,
the two-cylinder compressor being structured to switch between two operation modes including a single operation in which one of the two compression units is brought into a non-compression state, and a parallel operation in which both of the two compression units are brought into a compression state in accordance with operation conditions,

a heat-rejecting-side heat exchanger;
an expansion valve;
a heat-removing-side heat exchanger,
the two-cylinder compressor, the heat-rejecting-side heat exchanger, the expansion valve, and the heat-removing-side heat exchanger being connected to one another;

a controller configured to,
supply drive power to the electric motor of the two-cylinder compressor;
identify which one of the two operation modes is currently operating based on an electric signal acquired from an inverter drive control device; and
determine rotating frequency of the electric motor based on a result of determination of an operation mode detecting-determining unit so that a temperature of a target object is brought close to a set value, to control the inverter drive control device, and

a closed container into which the electric motor and the two compression units are inserted,
wherein the two-cylinder compressor passively switches an operation mode between the two operation modes when a pressure within the closed container changes in accordance with the operation conditions.

2. The heat pump apparatus of claim 1 , wherein the controller is further configured to,
determine that the operation mode is the single operation when a primary component of the rotating frequency of the electric motor is dominant in frequency components of a current waveform of a drive current supplied from the inverter drive control device to the electric motor.

3. The heat pump apparatus of claim 1 , wherein the controller is further configured to,
determine that the operation mode is the single operation when a primary component of the rotating frequency of the electric motor is dominant in frequency components of a torque fluctuation waveform calculated based on a drive current supplied from the inverter drive control device to the electric motor.

4. The heat pump apparatus of claim 1 ,
wherein at least one of the two compression units of the two-cylinder compressor includes,
a cylinder having a cylindrical cylinder chamber formed therein,
a piston arranged on an eccentric shaft portion of a drive shaft of the electric motor, and configured to perform eccentric rotary motion in the cylindrical cylinder chamber, and
a vane slidably arranged so that a distal end portion of the vane abuts on the piston, the vane partitioning the cylindrical cylinder chamber into two spaces,

wherein the at least one of the two compression units is constructed in a rotary compressor type so that a suction pressure is applied to the distal end portion of the vane, whereas a pressure of refrigerant discharged from the two compression units is applied to a rear end portion of the vane, that a pulling force is also applied to the vane in a direction of moving the vane to the rear end portion side, and that in accordance with the operation conditions, an operation state is switched between the compression state in which the distal end portion of the vane is held in contact with the piston, and the non-compression state in which the distal end portion of the vane is separated away from the piston, and
wherein the one of the two compression units includes a contact component arranged on a surface of the vane for retaining the vane while being in contact with the vane when the vane is separated away from the piston.

5. The heat pump apparatus of claim 4 , wherein the pulling force comprises any one of an elastic force, an inertial force, and a magnetic force.

6. The heat pump apparatus of claim 1 , wherein the controller is further configured to,
when detecting switching of the operation mode based on the result of determination, determine the rotating frequency of the electric motor so that cooling capacity or heating capacity of the heat pump apparatus has an equal value before and after the switching of the operation mode, to thereby control the inverter drive control device.

7. The heat pump apparatus of claim 6 ,
wherein the controller is further configured to,
when switching the operation mode from the single operation to the parallel operation, control the rotating frequency so as to aim the rotating frequency greater than 50% of the rotating frequency during the single operation before the switching, and
when switching the operation mode from the parallel operation to the single operation, control the rotating frequency so as to aim the rotating frequency less than 200% of the rotating frequency during the parallel operation before the switching.

8. The heat pump apparatus of claim 6 , wherein the controller is further configured to,
when switching the operation mode from the parallel operation to the single operation, set a target of the drive current so that a maximum value of the drive current supplied to the electric motor is temporarily smaller than a maximum value during the parallel operation.

9. The heat pump apparatus of claim 2 , wherein the controller is further configured to,
apply an FFT analysis to the current waveforms and calculates intensities of the frequency components.

10. The heat pump apparatus of claim 3 , wherein the controller is further configured to,
apply an FFT analysis to the torque waveforms and calculates intensities of the frequency components.

11. A heat pump apparatus, comprising:
a two-cylinder compressor including
an electric motor, and
two compression units to be driven by the electric motor,

the two-cylinder compressor being structured to switch between a single operation in which one of the two compression units is brought into a non-compression state, and a parallel operation in which both of the two compression units are brought into a compression state,
a heat-rejecting-side heat exchanger;
an expansion valve;
a heat-removing-side heat exchanger,
the two-cylinder compressor, the heat-rejecting-side heat exchanger, the expansion valve, and the heat-removing-side heat exchanger being connected to each other,
at least one of the two compression units of the two-cylinder compressor includes,
a cylinder having a cylindrical cylinder chamber formed therein,
a piston arranged on an eccentric shaft portion of a drive shaft of the electric motor, and configured to perform eccentric rotary motion in the cylindrical cylinder chamber, and

a vane slidably arranged so that a distal end portion of the vane abuts on the piston, the vane partitioning the cylindrical cylinder chamber into two spaces; and
a controller configured to,
supply drive power to the electric motor of the two-cylinder compressor;
output a conduction signal of a switch under a state in which the distal end portion of the vane of the at least one of the two compression units is separated away from the piston and the vane is stopped;
identify that a current operation mode is the single operation when acquiring the conduction signal output from the switch, and identifies that the current operation mode is the parallel operation when acquiring no conduction signal; and
control output frequency of an inverter drive control device based on a result of identifying so that a temperature of an object is brought close to a set value, and

a closed container into which the electric motor and the two

Assignees

• Mitsubishi Electric Corp

Inventors

• Yokoyama Tetsuhide
• Shinomoto Yosuke
• Moroe Shogo
• Satake Akira
• Fujitsuka Masashi
• Mori Takeshi
• Kato Taro
• Maeyama Hideaki
• Tada Keiko

Classifications

• F25B2700/2104

  of an indoor room or compartment · CPC title

• F25B2600/021

  Inverters therefor · CPC title

• F25B2400/074

  with multiple cylinders · CPC title

• F25B2313/0314

  Temperature sensors near the indoor heat exchanger · CPC title

• F25B13/00

  Compression machines, plants or systems, with reversible cycle (defrosting cycles F25B47/02) · CPC title